US8411195B2ActiveUtilityA1
Focus direction detection confidence system and method
Est. expiryApr 1, 2031(~4.7 yrs left)· nominal 20-yr term from priority
H04N 23/67
63
PatentIndex Score
1
Cited by
6
References
24
Claims
Abstract
An apparatus and method for determining confidence in focus direction detection, including the steps of capturing a plurality of images, calculating sets of matching errors and blur difference estimations relating to the images, capturing a plurality of object images; calculating sets of matching errors and blur difference estimations relating to the images, calculating a confidence indicator as a function of either the matching errors or blur difference estimations, and automatically adjusting a focus control element in response to said confidence indicator exceeding a threshold value.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1. An apparatus for electronically capturing images, comprising:
(a) an imaging device;
(b) a focus control element coupled to the imaging device;
(c) a processor coupled to the imaging device and the focus control element;
(d) memory coupled to the computer processor and configured for retaining images captured from the imaging device and for retaining programming executable by the computer processor; and
(e) programming executable by the computer processor for carrying out steps comprising:
capturing a plurality of object images;
calculating sets of matching errors and blur difference estimations relating to the images;
calculating a confidence indicator as a function of either the matching errors or blur difference estimations; and
automatically adjusting the focus control element in response to said confidence indicator exceeding a threshold value;
wherein the confidence indicator is calculated according to the equation:
E
=
E
1
-
E
2
k
E
·
(
E
1
+
E
2
)
+
1
where E is the confidence indicator, E 1 and E 2 are estimations of error for first and second directions, and k E is a non-negative constant.
2. An apparatus as recited in claim 1 , wherein the confidence indicator is a function of only matching errors.
3. An apparatus as recited in claim 1 , wherein k E is chosen so that the ratio between standard deviations of wrong data sets associated with the captured images is maximized.
4. An apparatus as recited in claim 1 , wherein the confidence indicator is calculated according to the equation:
I
=
I
1
-
I
2
k
I
·
(
I
1
+
I
2
)
+
1
where I is the confidence indicator, I 1 and I 2 are blur difference estimation iteration numbers for first and second directions, and k I is a non-negative constant.
5. An apparatus as recited in claim 1 , wherein the confidence indicator Is further calculated according to the equation:
C
=
E
k
·
I
+
1
where C is the combined confidence indicator,
I
=
I
1
-
I
2
k
I
·
(
I
1
+
I
2
)
+
1
,
I 1 and I 2 are blur difference estimation iteration numbers for first and second directions, and k I is a non-negative constant.
6. An apparatus as recited in claim 1 , wherein automatically adjusting the focus control element comprises scanning in one direction associated with the calculated confidence indicator.
7. An apparatus as recited in claim 1 :
wherein the calculated sets of matching errors and blur difference estimations relating to the images are evaluated against an iteration number bound; and
wherein the confidence indicator is only calculated if the iteration number bound is not exceeded.
8. An apparatus as recited in claim 1 , wherein the imaging device comprises a still image camera, a video image camera, or a combination still and video image camera.
9. A method for electronically capturing images, comprising:
(a) capturing a plurality of object images;
(b) calculating, within an electronic device, sets of matching errors and blur difference estimations relating to the images;
(c) calculating a confidence indicator, within the electronic device, as a function of either the matching errors or blur difference estimations; and
(d) automatically adjusting a focus control element in response to said confidence indicator exceeding a threshold value;
(e) wherein the confidence indicator is calculated according to the equation:
E
=
E
1
-
E
2
k
E
·
(
E
1
+
E
2
)
+
1
where E is the confidence indicator, E 1 and E 2 are estimations of error for first and second directions, and k E is a non-negative constant.
10. A method as recited in claim 9 , wherein k E is chosen so that the ratio between standard deviations of wrong data sets associated with the captured images is maximized.
11. A method as recited in claim 10 , wherein the confidence indicator is further calculated according to the equation:
I
=
I
1
-
I
2
k
I
·
(
I
1
+
I
2
)
+
1
where I is the confidence indicator, I 1 and I 2 are blur difference estimation iteration numbers for first and second directions, and k I is a non-negative constant.
12. A method as recited in claim 10 , wherein the confidence indicator is further calculated according to the equation:
C
=
E
k
·
I
+
1
where C is the combined confidence indicator,
I
=
I
1
-
I
2
k
I
·
(
I
1
+
I
2
)
+
1
,
and I 2 are blur difference estimation iteration numbers for first and second directions, and k I is a non-negative constant.
13. A method as recited in claim 9 , wherein automatically adjusting the focus control element comprises scanning in one direction associated with the calculated confidence indicator.
14. A method as recited in claim 9 :
wherein the calculated sets of matching errors and blur difference estimations relating to the images are evaluated against an iteration number bound; and
wherein the confidence indicator is only calculated if the iteration number bound is not exceeded.
15. A method recited in claim 9 , wherein the confidence indicator is a function of only matching errors.
16. A method recited in claim 9 , wherein the imaging device comprises a still image camera, a video image camera, or a combination still and video image camera.
17. A non-transitory computer-readable media containing a computer program executable on a processer which is configured for automatically estimating camera focal depth of an object in response to steps comprising:
(a) capturing a plurality of object images;
(b) calculating sets of matching errors and blur difference estimations relating to the images;
(c) calculating a confidence indicator as a function of either the matching errors or blur difference estimations; and
(d) automatically adjusting a focus control element in response to said confidence indicator exceeding a threshold value;
(e) wherein the confidence indicator is calculated according to the equation:
E
=
E
1
-
E
2
k
E
·
(
E
1
+
E
2
)
+
1
where E is the confidence indicator, E 1 and E 2 are estimations of error for first and second directions, and k E is a non-negative constant.
18. A non-transitory computer-readable media as recited in claim 17 , wherein k E is chosen so that the ratio between standard deviations of wrong data sets associated with the captured images is maximized.
19. A non-transitory computer-readable media as recited in claim 18 , wherein the confidence indicator is further calculated according to the equation:
I=((I 1 )−(I 2 ))/(k 1 ((I 1 )+(I 2 ))+1 where I is the confidence indicator, I1 and I2 are blur difference estimation iteration numbers for first and second directions, and k˜ is a non-negative constant.
20. A non-transitory computer-readable media as recited in claim 17 , wherein the confidence indicator is further calculated according to the equation:
C=E/k.I+I
where C is the combined confidence indicator, I=((I 1 )−(I 2 ))/(k 1 ((I 1 )+(I 2 ))+1, I1 and I2 are blur k 1 .(I1+I2)+1 difference estimation iteration numbers for first and second directions, and k˜ is a non-negative constant.
21. A non-transitory computer-readable media recited in claim 17 , wherein the confidence indicator is a function of only matching errors.
22. A non-transitory computer-readable media recited in claim 17 , wherein automatically adjusting the focus control element comprises scanning in one direction associated with the calculated confidence indicator.
23. A non-transitory computer-readable media recited in claim 17 :
wherein the calculated sets of matching errors and blur difference estimations relating to the images are evaluated against an iteration number bound; and
wherein the confidence indicator is only calculated if the iteration number bound is not exceeded.
24. A non-transitory computer-readable media recited in claim 17 , wherein the imaging device comprises a still image camera, a video image camera, or a combination still and video image camera.Cited by (0)
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